Semi-automatic telephone system



A. J. SEYMOUR.

SEMI-AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED MAR. 19, 1919.

Patented May 10, 1921.

2 SHEETS-SHEET I Ztzr" ggmuur .HIZU- InUE n A. J. SEYMOUR.

SEMI-AUTOMATIC TELEPHONE SYSTEM. APPLICATION FILED MAR. 19. 1919.

2 SHEETS-SHEET 2.

1,377,225, Patented May 10, 1921.

Ii-membr- HFZZ-LUFJEiLfmUUI UNITED STATES PATENT OFFICE.

ARTHUR J SEYMOUR, OF 8'1. PAUL, MINNESOTA, ABSIGNOB 'I'O AUTOMATIC ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OI ILLINOIS.

SEMI-AUTOMATIC TELEPHONE SYSTEM;

Specification of Letters Patent.

Application filed March 19, 1919. Serial No. 283,466.

. and a resident of St. Paul, in the county of Ramsey and State of Minnesota, have invented certain new and useful Improvements in Semi-Automatic Telephone Systems, of which the following is a specification.

. My invention relates in general to a socalled semi-automatic system in which it is desired to have interconnection between a manual and an automatic exchange and Where it is therefore necessary to provide the operator in the main exchange with means for connecting with and operating the automatic switches in the automatic section of the exchange.

More specifically my invention relates to an improved trunk circuit for use by an operator in extending calls to an automatic exchange, having improved means for automatically switching an operators calling device into and out of connection with said trunk circuit to allow control of the switches. These and other features of my invention will be more fully pointed out in connection with the accompanying drawings in which- Figure 1 shows a well known type of manual cord circuit B together with a trunk circuit C accessible thereto. In the trunk circuit C is a calling device C. D. which is common to a plurality of trunk circuits similarto C, and adapted to be automatically connected to each one as used and disconnected thereafter either automatically or at the operators will, as will hereinafter more fully appear.

Fig. 2 shows an automatic selector switch D individual to the trunk circuit C and controlled thereover and having access to a number of connector switches H of well known type which complete the conmotion to a called line. The selectors and connectors of this system may be of any approved type such as the Strowger type of vertical and rotary switch, it being understood that any type of switch may be 'used and any type of cord circuit may be used without departing from the spirit of my invention.

I will now describe ,the operations when the operator at cord circuit B receives a call for a Subs riber in the automatic ex change. In such a-call the operator at B inserts the plug P into the jack P associated withan outgoin -trunk line to the automatic exchange. s soon asithis plug is inserted, a circuit is closed for the relay 2 of the trunk circuit extendin from ound through said relay, sleeve 0 jack and plug low resistance relay 3 of the cord circuit andthrough a lamp 4: to battery. Relays 2 and 3 energize over this circuit, relay 2 operates to close a circuit through sprlngs 5, springs 6 and 7, and relay 8 to batte Relay 2 also closes one point in a circult of the relay 9-at springs 10, which circuit is not completed at this time. Relay 8 also energizes to open the talking circuit at springs 11 and 12, closes a circuit for the guard lamp 13 at springs 14 and connects the calling device sprlngs 16 across the called end of the trunk circuit through springs 11 and. 15, relay 18, and the springs 17.

The calling device C. D. is therefore connected across thetrunk circuit in series with the line relay 20 of the selector D (Fig. 2) which energizes to close a circuit for slow release relay 21 through its front contact. Relay 21 in the usual manner operates to prepare the circuits of the various magnets and relays of the switch D.

Now when the operator at cord circuit B sees the guard lamp 13 lighted, she operates the calling device C. D. in accordance with the digits of the wanted subscribers number. Before the operation of the calling device, the springs 22 and 23 are closed as shown connecting ground to the series circuit of the calling device and the line relay of the switch D. It will be seen therefore that the relay 18 and the lower Windin of relay 20 of switch D are short circuited Now when the calling device is first operated the spring 22 is moved out of engagement with the spring 23 by the engagement therewith of spring 24, thereby removing the original short circuit about relay 18 and the winding of relay 20 and substituting instead a direct short circuit about the winding of relay 18 only, so that the line relay 20 is now energized over the two sides of' the line in series, with the calling device Patented May 10, 1921.

and both its windings in series durinlg impulses. The operation'of the selector and of the connector H will be explained only in general as the operation of such switches is old in'the art and therefore well known.

The line rela .2()-operates in response to the first digit bf the called number to control the magnet 25 to step the, wipers to a level of. contacts, then relay 26 operatesto close a circuit for magnet 27 to ste the wlpers onto an idle set of contacts in t e selected level, the relay 28 acting as atest relay to stop the operation of magnet 27 when such idle trunk .is reached. Then the switching relay 29 is operated to cut the connection through to the Y line relay of the connector switch H. The

line rela- 3O responds to the next digit to operate the vertical magnet 31 throughcontacts of slow relay 32 which remalns energized during impulses. Magnet 31 raises the wipers of the switch H to some level of the bank and as the series relay 33 falls back after this digit, the circuit of the rotary magnet. 34 is prepared. The operation of relay 30 by the next digit operates magnet 34 to step the wipers to the contacts of thejcalled line, relay 35 energizing in multiple w th magnet 34 to hold the busy relay connected to the private wiper so that'lf the line is busy said relay 36 will energize to transmit a busy signal to the-talking circuit. If the line is idle then relay 37 will energize after the relay 35 falls back and the called line is connected to the ringing circuit for signaling purposes. When the called subscriber responds by removing his receiver, a circuit is completed for the ring cut off relay 38, which energizes to disconnect the ringing circuit and connects the back bridge relay 39 across the called line. Relay 39 now energizes and reverses the connections of the line relay 30 with regard to the extended talking circuit, thereby reversing the direction of current fiow in the trunk circuit C (Fig.1). When this reversal takes place a circuit is completed from ground through springs 23 and 22, relay l8, springs 15 and 11, springs 40 and 41, springs 42 and 43 and upper winding of relay 30 to battery. Therefore it will be seen that relay 18 is no longer short circuited butis energized over this circuit in series with relay 30. Relay 18 upon energizing, closes a circuit from battery through springs 45, springs 46 and 47, relay 9, and springs 10 to ground. Relay 9 locks itself energized through springs 47 and 48 to battery and opens the circuit of the slow relay 8 at springs 6 and 7 and connects ground to one side of the talking circuit through spring 6 and its front contact and back contact of relay 49. Relay 8 falls back at this time disconnecting the calling device C. D. from the trunk circuit C and at the same time a circuit is completed for the relay 4? fr m g oun a t e cord c rcu t through finishes operating the 7 arranged this trunk the plug and jack relay 49 springs 12 and 11, and upper winding of i'elay 30 to battery. Relay 49 on energizing closes the it is answered, then she will immediately press the non-locking key 56 as soon as she dial. In this case the circuit of relay 9 is closed through the springs 56 instead of through the springs of relay 18 and relay 9 will look as before explained to open the circuit of relay 8 at springs 6 and 7 and thus remove the calling device from across the trunk. At the same time a circuit is closed as before from ground through springs 5, springs 6 and 57 springs 52 and 51, springs 58 and 59, springs 60 and 61, and upper winding of line relay 30 to battery. This circuit prevents rela 30 from deenergizing and releasing the swltches before the called man answers. In-this case when the called man answers relay 49 is immediately energized due to the reversal of current and the closure of its springs allows relay 54 at the cord circuit tooperate and put out its supervisory signal.

It will be seen therefore that I have provided a very simple and efficient trunk circuit for use from a manual cord circuit to an automatic switch and one which cuts the operations of the operator to a minimum. That is, when the operator seizes this trunk a calling device is automatically thrown across the trunk which device may of course be common to a number of such trunks and the operator simply dials the number and then operates the key which disconnects the device and allows it to be used on another trunk circuit and also prepares the circuits so that when the called subscriber responds, the talking circuit is cut through and proper supervision given. In addition I have so circuit that in case the operator does not operate the key but leaves the calling device across the trunk then the response of the called subscriber will automatically cut off the device as well as perform the other functions just as though the key had been pressed first. aving fully described and ascertained the, features and aspects of my invention, what I consider to be new and desire tohave protected by Letters Patent will be pointed out in the appended claims. 1

W hat I claim as my invention is:

1. In a semi-automatic telephone system, a cord circuit, trunk lines accessible thereto, a calling device, means for automatically associating said device with a trunk .line when seized by the cord circuit, and means Controlled by a called subscriber to whom a connection is extended for removing the calling device from the trunk line.

2. Ina semi-automatic telephone system, a cord circuit, trunk lin accessible thereto, a calling device, a' relay or automatically associating said device with a trunk line when seized by the cord circuit, andmeans for removing the calling device from the I trunk line.

4. In a telephone system, an operators cord circuit, a supervisory signal therefor, trunk lines acccessible to said cord circuit and adapted to be seized thereby, means controlled by the seizure of one of said trunk lines for automatically connecting said calling device thereto, means controlled by the operator for disconnecting said device from the trunk line, and means controlled by the response of a called subscriber for operating said signal.

5. Ina telephone system, an operators cord circuit, a supervisory signal'therefor, trunk lines acccessible to said cord circuit and adapted to be seized thereby, electromagnetic means controlled by the seizure of oneof said trunk lines for automatically.

from the trunk line, and means controlled. by the response of a called subscriber for.

operating said si nal.

7. In a telephone system, an operators cord circuit, a signal in the cord circuit, automatic switches accessible to said cord circuit, trunk lines leading to said switches,

a calling device common to said trunk lines, automatic means controlled by the seizure of one of said sWitches-forconnecting said calling device to the trunk line leading to said switch, said switch under control of said calling device when controlled by the operator to extend a connection to a called line, andmeans controlled by the subscriber on the called line for disconnecting thedevice from the trunk line and-.for operating a signal in the cord circuit. I

8. In a telephone system, trunk lines, a calling device common to said trunk lines, means controlled. by the seizure of one of said trunk lines for bringing said calling device into operative relation with the seized trunk line, and means controlled either automatically or by the operator for removing the calling device from operative relation with the trunk.

9. In a telephone system, trunk lines, a calling device common to said trunk lines, means for seizing one of said trunk lines to extend a connection, means controlled by the seizure of said trunk line for connecting said calling device thereto, means controlled by said calling device for extending the connection to a called subscriber, and means controlled by the called subscriber for disconnecting said calling device.

10. Ina telephone system, trunk lines, a calling device common to said trunk lines, means for seizing one of said trunk lines to extend a connection/means controlled by the seizure of said trunk line for connecting said calling device thereto, means controlled by said calling device for extending the connection to a. called subscriber, and

means controlled by the called subscriber for disconnecting said calling device while the connection is established.

11. In a telephone system, trunk lines, a calling device common to said trunk lines, a cord circuit for seizing one of said trunk lines to extend a connection, means controlled by the seizure of said trunk line for connecting said calling device thereto, means controlled by said calling device for extending the connection to a called subscriber, and means controlled by the called subscriber for disconnecting said calling device.

12. In a telephone system, trunk lines, a calling device common to said trunk lines, means for seizing one of said trunk lines to extend a connection, a relay controlled by the seizure of .said trunk line for connecting said calling device thereto, means controlled by said calling device for extending the connection to a called subscriber, and means controlled by the called subseriber for disconnecting said calling device.

13. In a telephone system, trunk lines, calling device common to said trunk lines, means for seizing one of said trunk lines to extend a connection, a relay "controlled by the seizure of said trunk line for connecting said calling device thereto, automatic switches controlled by saidcalling device for exte di g the connection to it call d subscriber, and means controlled b the called subscriber for disconnecting sai calling device.

14. In a telephone system, trunk lines, a cord circuit, a calling device common to said trunk lines, said trunk lines accessible to said cord circuit, means controlled by the connection of said cord circuit and one of said trunk lines for connecting the calling device to the trunk line, a relay for disconnecting the calling device. from the trunk line, and a key for preventing the operation of said relay and disconnecting said calling device.

15. In a semi-automatic telephone system in which a cord circuit, a trunk line and an automatic switch are successively connected to extend a connection to a calle subscriber, a calling device, means for connecting the calling device to the trunk line when the cord and trunk line are first connected, a relay which operates when the called subscriber answers to disconnect the calling device, and a key for also disconnectmg said calling device and rendering sald relay 1noperative.

16. In a, telephone system, trunk l1 nes, means for seizing one of said trunk lines to extend a connection, a calling device for said trunk lines, a relay for connecting said calling device to a trunk line when that trunk line is seized, another relay for. disconnecting said calling device and for closing one of the conductors of said trunk line, and another relay for ductor of said trunk line.

17. In a telephone system, a cord circuit, a signal therein, a trunk line accessible thereto, said trunk line having one point normally open and another point normally closed, a; calling device for said trunk line, means controlled by the seizure of said trunk line for connecting said calling device thereto and for opening said normally closed point, automatic means for disconnecting said callin device and closing said normally closed point, and for then closing said normally open point to control said slgnal.

18. In a telephone system, a cord circuit having a plug and a signal, a trunk line having a jack, a calling device automatically connected to said trunk line when said plug is inserted in the jack, means controlled by said device for extending a connection from said trunk line to a called subscriber, a key for disconnecting said calling device, and means controlled by the called subscriber for operating said slgnal if the key has been pressed and for first disconnecting the calling device and then operating the signal 1f the key has not been pressed.

Signed by me at St. Paul, Ramsey county, State of Minnesota, this eleventh day of March, 1919.

ARTHUR J. SEYMOUR- closing another con-' 

